This invention relates generally to pruning trees and more particularly to a mechanized tree pruner wherein the specific improvement is to the individual blade members combined into pruner belts.
On Nov. 1, 1988 U.S. Pat. No. 4,781,228 issued and was assigned the assignee of the present invention. The disclosure in U.S. Pat. No. 4,781,228 is incorporated herein by this reference. The patent discloses a mechanized tree pruner having a pair of delimbing stations, each of which has so-called knife chains mounted on grapple arms. The chains are composed of individual shearing blades pinned together so as to be flexible and to encircle a tree to be pruned or delimbed. The blade elements in the tree pruner disclosed in the aforementioned patent had flat blades and, as a consequence when the pruner belts were wrapped about the tree, the blades were offset correctly with respect to the tree only where they impacted the tree at their center points leaving longer stobs where they were joined together at the dowel pins.
The present invention represents an improvement in the prior blade design in that curved blades have been found to minimize stob lengths since they are offset a correct amount over their entire width and over the full range of the tree diameters to be pruned. The typical diameter ranges for tree pruning will be from 3-10 inches.
Accordingly, from the foregoing, one object of the present invention is to provide a tree pruner where stob length is minimized.
This and other objects of the present invention will be better understood upon reading the specification to follow in conjuction with the attached drawing.